Micro-electromechanical systems (MEMS) are used in a variety of applications, including optical display systems. Such systems often include a light source that projects light rays onto a light modulator panel. In many optical display systems, the light modulator panel includes an array of MEMS devices commonly referred to as pixels. The pixels modulate light to control its color, intensity, hue, or other characteristics.
For example, some pixels include reflective plates that are selectively tilted to direct light along a desired path. More specifically, when such pixels are in an ON state, the reflective plate is tilted such that the pixels direct light incident thereon to the display optics, which focus the light onto a display surface. Similarly, when such pixels are in an OFF state, the reflective plate is oriented such that the light is directed away from the display surface. By controlling the frequency with which the light is directed from each pixel to the display surface, each pixel is able to produce an output that varies from light to dark on the display surface. By properly controlling an array of pixels, a full image may be formed.
Some systems activate a pixel by selectively charging the reflective plate. The charge on the reflective plate creates an electrostatic force that causes the reflective plate to tilt. The charge is frequently provided by a charge source, such as an electron gun that selectively directs an electron beam to the pixel. An insulator is frequently provided between adjacent pixels to reduce the possibility that charge from one pixel will flow to an adjacent device. Such insulators may become partially conductive when subjected to the electron beam. If the insulator becomes sufficiently conductive, charge may unintentionally flow from one pixel to another, thereby reducing the effective operation of the intended pixel.